To make appropriate ISFM recommendations for farmers, it is imperative to have a good understanding of the roles of the different soil nutrients to the cocoa trees and yield. This knowledge is sparsely available, and therefore the partners of the CocoaSoils program are setting up ‘Core and Satellite Research for Development’ trials to help provide site specific ISFM/fertilizer recommendations across West Africa. The Core trials are long-term trials of at least two hectares, where fertilizers will be applied in different quantities and combinations, and responses in yield will be carefully measured. In addition to the Core Trials, smaller trials (Satellite Trials) will be set up in farmers’ fields to test different fertilizer combinations and shade interactions to examine the effects on yield under field conditions.